Fish-paste products such as kamaboko (fish cakes), chikuwa (fish sticks), and agekamaboko (fried fish cakes) are generally produced by: grinding or mashing (stirring and mixing) raw materials, for example, fish flesh such as surimi or minced flesh (hereinafter referred to as surimi), seasonings, toughening agents such as starch, and water; forming the mixture into a suitable shape; and heating the molded material.
In this production process, elasticity specific to the fish-paste product is imparted in the following manner. When salt is added to fresh fish flesh surimi, and the mixture is ground, among the fish flesh proteins, salt-soluble proteins, particularly actomyosin, are eluted out to form a so-called sol, and thus surimi having very high tackiness is obtained. When this is heated, sol-like proteins are thermally coagulated into a gel having extremely great elasticity. This elasticity is a characteristic of the fish-paste product and is called "rubbery texture". It is said that the greater the elasticity is, the stronger is the rubbery texture. The rubbery texture occurs because actomyosins are bonded to each other upon heating to form a steric net structure.
Heretofore, in the grinding (stirring/mixing) step of a process for producing a fish-paste product, raw materials such as surimi, salt, and seasonings have been sequentially charged into a bath-type grinder (a stirring/mixing machine), a cutting mixer (Silent Cutter, trademark) or the like. The mixture has been stirred and mixed for a relatively long period of the time, and then salted surimi has been removed as a starting material for molding.
However, actomyosin eluted by salt addition is readily and rapidly denatured. The denaturation of actomyosin can occur even in the stirring step. In the case of long stirring, the ability of fish flesh to form a gel is not completely utilized. In the prior batch-type process, the salted surimi for molding tends to lag residually, and therefore in the material molded after a delay, "premature network formation" occurs. A product molded from the premature network-formed surimi exhibits remarkable reduction in gel. Thus, it is impossible to fully utilize the inherent ability of the raw material fish flesh to form a gel.
An object of the present invention is to provide a process by which the problems described above can be overcome and by which fish-paste products having "strong rubbery texture", i.e., excellent gel strength, can be produced.